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March/April 2019

SkyNews, the magazine of astronomy and stargazing, features complete observing information, expert equipment reviews, star chart — everything beginners and intermediate amateur astronomers and astrophotographers need. Edited by astronomy author Terence Dickinson, published in Canada, writers include equipment guru Alan Dyer, comet hunter David Levy, wilderness astronomer Peter McMahon, Ken Hewitt-White, Gary Seronik, Ray Villard

Royal Astronomical Society of Canada
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blinded by the light

IGHT POLLUTION is one topic I’d prefer not to write about ever again. But I expect I will—and probably several times. Although it can be eliminated with the flick of a switch (literally!), the problem isn’t going away any time soon. It’s also true that by definition, light pollution is pure waste. It benefits no one, but the costs are borne by all.Light pollution is largely a by-product of ignorance. No one would voluntarily agree to pay higher taxes for streetlights to illuminate the undersides of airborne geese. We wouldn’t deliberately deprive ourselves and our children of the splendours of the night sky. No one interested in the natural world would sign on for disrupting the migratory patterns of birds and the nocturnal habits of all kinds of critters. No…

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a bonus from kepler

THE PRIME MISSION of the now decommissioned Kepler spacecraft was to look for transiting exoplanets by monitoring the way certain stars subtly change in brightness. Before running out of fuel, Kepler gazed at two areas of sky that were also under scrutiny by ground-based observatories. Both cosmic patches teem with galaxies—each containing billions of stars. And one of them exploded while Kepler was watching.The exploding star—SN2018oh—is a Type Ia supernova, the kind astronomers use to track the expansion of the universe. “The observations are exquisite,” says Ryan Foley of the University of California, Santa Cruz, “because we have images from Kepler every 30 minutes, starting from before the explosion all the way past its peak brightness.”A typical Type Ia supernova brightens for three weeks before slowly fading away. But Kepler…

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boulder world

BOULDERS GALORE This mosaic of asteroid Bennu, taken from a distance of 24 kilometres, reveals a boulder-strewn surface that’s more rugged than scientists expected. The boulder at lower right is one of the biggest, measuring 50 metres high and 55 metres wide. (COURTESY NASA/GODDARD/UNIVERSITY OF ARIZONA)ASTEROID BENNU is a 500-metrewide pile of rubble that orbits the Sun every 1.2 years. It passes very close to Earth every six years, which makes it a near-Earth object (NEO). Astronomers estimate there are nearly 20,000 NEOs, and the OSIRIS-REx sample-return mission is an opportunity to engage with one of them.OSIRIS-REx arrived at Bennu only late last year, but scientists are already excited by what they’ve seen. Data obtained from the spacecraft’s two spectrometers reveal the presence of hydroxyls (molecules that contain oxygen and…

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a planet for barnard’s star

IN 1963, AN AMAZING DISCOVERY was announced: A planet circled Barnard’s Star, a mere six light-years away. Peter van de Kamp, director of the Sproul Observatory in Pennsylvania, declared that this world was about 1.6 times Jupiter’s mass and orbited some 4.4 astronomical units from the red dwarf star. He detected its presence by searching for a minuscule wobble in the star’s motion, caused by the subtle gravitational tug of a planet as it circled its sun. But other astronomers couldn’t replicate van de Kamp’s observations, and by the mid-1970s, the idea was discarded.Fast-forward to late 2018. Using observations from seven different instruments, spanning 20 years of measurements, a team of astronomers led by Ignasi Ribas of the Institute of Space Studies of Catalonia, Spain, announced they’re confident that a…

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starship voyager

IN 1972, ENGINEERS at the Jet Propulsion Laboratory (JPL) in California recruited Edward Stone, a 36-year-old Caltech associate professor, to be the project scientist for a proposed Mariner Jupiter-Saturn ’77 mission. That mission morphed into the Voyager 1 and 2 flights to the outer planets and beyond. On November 5, 2018, Voyager 2 exited the Sun’s heliosphere and entered interstellar space, joining Voyager 1, which crossed the boundary in 2012. Stone, now 82 but still the Voyager project scientist, was delighted to witness the crossing. “There is still a lot to learn about the region of interstellar space immediately beyond the heliopause,” he says.The most compelling evidence of Voyager 2’s exit from the heliosphere came from its onboard Plasma Science (PLS) experiment. Until recently, the space surrounding Voyager 2 was…

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earth invades mars, again

A LITTLE INSIGHT NASA’s InSight spacecraft rests on Elysium Planitia on Mars. This selfie shows the lander’s very clean solar panels and the science instruments nestled between the panels. The copper-coloured dome is the seismometer, which has since been placed on the Martian surface. (COURTESY NASA/JPL-CALTECH)NASA’S INSIGHT SPACECRAFT successfully landed on Mars on November 26, 2018. Its two-year mission: to examine in detail the red planet’s crust, mantle and core.To fulfill this goal, InSight carries three science instruments. The seismometer, sitting on the surface just beyond the spacecraft, will measure Mars quakes (assuming there are any) and will provide a glimpse of the planet’s internal activity. The heat-flow probe, after burrowing almost five metres into the Martian ground, will record how much heat is flowing up from the interior. Finally,…